Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Using a recent grant from the Bill and Melinda Gates Foundation, Andrew Fung and his colleagues at the University of California, Los Angeles are developing Maliva, a malaria-detecting gum that could offer cheap, new way to diagnose or monitor diseases.

"Wherever you sell candy, you could sell this gum," said Fung.

A person is infected with malaria when a female Anophelesmosquito, searching for blood to feed her young, bites a person. Six to 14 days after exposure, the infected individual will exhibit various symptoms, such as fever, chills, vomiting, a lack of energy (caused by the malaria parasites bursting out of red blood cells), and even convulsions.

To diagnose malaria, scientists draw a small blood sample and examine it under a microscope, searching for darker than normal red blood cells, which are infected by malaria parasites.

For regions without microscopes or experienced staff where malaria is prevalent, doctors currently use an antigen test. Using a single drop of blood, the tests detect the presence of several molecules made by the malaria parasites and released into human blood.

Areas that can't even afford the antigen tests, or where even a drop of blood is taboo, could use a new method to detect malaria.

Maliva could be that test, since three of the proteins that the blood antigen tests detect can also be found in saliva, according to a study released last year.

The initial idea to provide the gum with its malaria-detecting properties is to incorporate magnetic nanoparticles into the gum.

When a person chews the gum, saliva, containing molecules produced by the malaria parasites, pour into the mouth. The magnetic nanoparticles are tipped with antibodies that latch onto these very molecules.

After a few minutes chewing, the gum would be removed and placed on a paper strip. The nanoparticles, bound to the malaria proteins, would show up as a thin line. No line, no malaria.

Fung and his colleagues hope to have a working prototype of Maliva by next year. They plan to begin field tests with the gum shortly thereafter.

The project is in its beginning stages, but it's an exciting idea — one that more researchers are pursuing, according to David Wong.

Wong, a doctor at UCLA not involved with Fung's research, lead a recent National Institutes of Health consortium mapping the various proteins found in human saliva.

Using saliva, instead of painful needle sticks, will become more common in the next few years, and for diseases other than malaria.

"This is just the tip of the iceberg," said Wong. "There is no reason why this method can't be used to detect other conditions as well."